Ostrich tuning is a novel guitar tuning wherein all of the strings are tuned to the same note. It produces a distinctive chorus effect when multiple strings are strummed together. In the late 1960s, Lou Reed pioneered the tuning in his work with the Velvet Undergound.
While ostrich tuning makes it impossible to play most standard guitar repertoire, it's ideal for creating lush drones and ambient textures. It also opens up some interesting fingering possibilities, allowing you to construct tightly-spaced chord voicings and tone clusters using small intervals like major and minor seconds.
The chorus effect arises from the slight, inevitable deviations in tuning between strings. This is similar in principle to the way that a chorus effect unit doubles a sound and detunes it by a few cents. Sympathetic resonances also come into play. Strummed open strings will tend to induce vibration in neighboring strings, because they all want to resonate at the same note. This can create a cascade of sympathetic resonances that will reinforce one another in a sort of positive feeback loop.
“Ostrich tuning” is a colloquial term that refers to the “The Ostrich,” a song by Lou Reed and the Primitives. The track is considered the first documented use of the tuning in popular music, and Reed coined the term “ostrich” to describe it retroactively. Reed would go on to use the tuning in the songs “Venus in Furs” and “All Tomorrow's Parties” on the 1967 album The Velvet Underground & Nico.
[Links - The Ostrich, Venus in Furs, All Tommorow's Parties]
Ostrich tuning may be referred to as a “trivial tuning” in more formal contexts. Trivial tuning is any tuning wherein the same note is repeated across all open strings. Trivial tunings are a subset of regular tunings, wherein all successive pairs of strings are the same interval apart. For example, the E standard guitar tuning does not quite qualify as a regular tuning; while almost all successive string pairs are a perfect fourth apart, the G and B strings are a major third apart.
Tuning a guitar from E standard to ostrich can result in significant differences in tension from string to string. Some strings might have to go several steps up, and some, several steps down. Very slack strings will suffer from intonation problems when you fret notes, and very tight strings can impose mechanical stress on your guitar and are liable to snap. These issues can contribute a sub-optimal ostrich experience.
If you plan to use ostrich tuning regularly, the ideal solution is to do a full conversion of a guitar, with a set of strings chosen specifically for ostrich tuning. Standard string sets are not well-suited to the tuning, and you’re better off using a string tension calculator to determine which string gauges will allow you to achieve a normal string tension when tuned to the note you’ve chosen. I like [D’addario’s String Tension Pro,] available here.
If you assemble a custom string set, you’ll have more leeway in choosing which octaves each string will be tuned to. I like to have the lowest string tuned to the lowest octave, with the next three strings tuned an octave above, and the highest two strings tuned yet another octave above that. This would be expressed as D-d-d-d-d’-d’, for example. Reed’s original tuning was D-D-D-D-d-d. Many variations are possible, and there's really no wrong way to do it.
Ostrich tuning is great for drone music and for creating textures and ambient sounds in styles like shoegaze and post-rock (especially when used in conjunction with effects pedals and reverb). It's also useful for playing the dense, dissonant tone clusters seen in abrasive rock and contemporary noise music, and for playing repetitive low pedal tones under the simple melodies seen in doom and sludge metal.
If you have a slide on hand, you should definitely try it out on your ostrich guitar. Experiment with tilting the slide to shift some of the strings slightly out of tune with the others.